A man who told hostages and police he had a gun was actually unarmed during a three-hour standoff that ended with officers shooting and killing him outside a North Carolina bank, police said Sunday.

Cary Police Chief Pat Bazemore said 19-year-old Devon Mitchell concealed an object inside a red toboggan hat and presented it as a gun, but that he didn't have a firearm. Mitchell had as many as seven hostages, though most were released during the course of the standoff on Thursday.

"Why Devon set all of this in motion, why he wanted all of us to believe that he had a weapon and was prepared to kill with it are questions that we will never have the answers to," Bazemore said. "But it is clear that that's what Devon wanted us to believe."

A bank employee called police at the beginning of the ordeal and told dispatchers that she was ordered to call by an armed man who was holding another worker at gunpoint, according to an audio tape of the 911 call. Police have said he didn't demand money.

At the end, Mitchell walked out holding what appeared to be a gun to the head of a hostage and police fired, killing the suspect. No one else was harmed.

"This information does not change that our officers did exactly what they were trained to do and what they were expected to do," Bazemore said of the shooting.

One expert said last week that the fact that Mitchell did not demand money from the bank teller could mean the standoff was a case of "suicide by cop" — a term used to describe when a suicidal person purposely induces a law enforcement officer to kill him.

In those cases, suspects want to die but are afraid to pull the trigger themselves, so they commit an offense knowing that officers would probably respond with deadly force, said Dr. Barry Perrou, a forensic psychologist and former commander of the Los Angeles County Sheriff's Hostage Negotiations Unit.

"Devon Mitchell was troubled," Bazemore said. "We've heard it over and over again in interviews after his death. And we all have to ask ourselves if someone could have done something that would have made a difference in that young man's life."

The chief says Mitchell's family does not want to talk to the media. The names of the hostages have not been released.

A city spokeswoman said the officers involved in the shooting were all on administrative duty, which is standard policy following a shooting.

The city officers were Ricky Burch, 45, a senior police officer who has been on the force since 1999; Sgt. Rick Glancy, 42, who has been on the force since 1993; Irvin Leggett, 42, a senior police officer on the force since 1998; and Chris Redig, 31, a master police officer on the foce since 2007.

Wake County Deputy Brad Manville was also involved in the shooting and is on administrative duty. He has been with the sheriff's department for about four years, sheriff's spokeswoman Phyllis Stephens said Sunday.

(This version CORRECTS Corrects quote that begins "This information. Updates with officers names.)